As is known, operating electronic devices produce heat. This heat should be removed from the devices in order to maintain device junction temperatures within desirable limits. Failure to remove heat can result in increased device temperatures, potentially leading to thermal runaway conditions. Several trends in the electronics industry have combined to make thermal management a significant consideration, including heat removal for electronic devices, particularly in technologies where thermal management has traditionally been less of a concern, such as CMOS. In particular, the need for faster and more densely packed circuits has had a direct impact on the importance of thermal management. First, power dissipation, and therefore heat production, increases as device operating frequencies increase. Second, increased operating frequencies may be possible at lower device junction temperatures. Further, as more and more devices are packed onto a single chip, power density (Watts/cm2) increases, resulting in the need to remove more power from a given size chip or module.
An alternate approach to traditional air-cooling of electronic devices or components is to use a cooling liquid. In a cooling system comprising a cooling liquid, the cooling liquid may be in direct or indirect contact with the electronic component to be cooled. In particular, the performance and reliability of high-power CMOS circuits may be improved using liquid-cooling, such as refrigeration or water, rather than air-cooling. In such a system, performance of the liquid cooling system can be a significant factor in the performance of the electronic component (e.g., processor, multichip module, or server) being cooled.
One method of handling a significant degradation in observed temperature(s) for a component being cooled is to cut the clock speed employed, for example, in half. Such a method lowers the power being generated by the logic device sufficiently so that damage concerns due to high temperatures are eliminated. The approach is essentially simple thermal protection to prevent damage to the logic device or component. More proactive methods of cooling system monitoring and replacement would be commercially advantageous.